Damping media for damping mechanical vibrations are known. Hydraulic oils, for example, have been suggested as damping media. However, these oils have the disadvantage that the heat formed when the damping medium is subjected to permanent load cannot be dissipated quickly enough, so that the oils become overheated and either foam or decompose.
Use has also been made of silicone oils containing hardening additives. These damping media undergo hardening under sudden load. Because of their limited flow properties, these dilatant damping media can only be used, however, for a few special damping processes. Damping media which harden also have the disadvantage of not possessing any noise-insulating property.
The U.S. Pat. No. 3,812,937 describes a damping medium for hydraulically-operating car shock absorbers. It consists of a low-viscosity petroleum oil, contains up to 20% by weight of an organophilic aminomontmorillonite that is prepared by reacting montmorillonite with an aliphatic amino salt, and contains acetonitrile.
The known hydraulic oil is a thickened oil which is not, however, suitable for damping high-frequency vibrations or for permanent loads because it is not able to dissipate the heat resulting from shock and/or tensile loads quickly enough. The petroleum oil starts to decompose at temperatures as low as about 82.degree. C., while the viscosity of the damping medium is already considerably reduced at temperatures below 82.degree. C.
The DE-OS No. 2 647 697 describes a damping medium dispersion comprising a liquid phase of silicone oil, mineral oil, polyglycol or a thermally stable, saturated aliphatic or aromatic carboxyl acid ester and, in the form of additives, graphite, wetting agents and viscosity stabilizers. The known damping medium dispersion is a non-hardened paste of relatively temperature-stable viscosity, which has good flow properties. However, the damping medium dispersion is made from relatively expensive starting materials.